A prior art sterilization system is described in U.S. Pat. No. 3,476,506, issued Nov. 4, 1969. This prior art patent discloses an ampule or source of sterilant, a gas release bag which contains the ampule, a liner bag which contains the gas release bag and the items to be sterilized, and a metal container which contains the liner bag. Ethylene oxide sterilizing gas from the ampule is released into the gas release bag and the sterilization gas in the gas release bag is released into the liner bag to sterilize items within the liner bag. After a period of time (e.g. 4 hours), virtually all of the gas that is contained within the ampule is diffused from the inside of the gas release bag into the liner bag, where it is held in contact with the items to be sterilized for the duration of the sterilizing cycle (e.g. 12 hours). During this time,, a significant portion of the gas is gradually released by the liner bag gas diffusion membrane into the space between the liner bag and the metal container. This gas escapes from the unsealed metal container into the ambient work area.
One problem with this prior art sterilization system was that the operator is exposed to the sterilizing gas in the work area and to the gas in the liner bag when the latter is opened upon completion of the sterilization cycle. This problem is overcome in the present invention by utilizing a post sterilization flush which minimizes the extent of residue sterilant in the surrounding work area.